The present invention relates to integrated circuits, and more specifically, to error protection in integrated circuits including a plurality of storage cells.
As integrated circuits continue to be made smaller many new dependability issues are becoming increasingly important. For example, it has long been known that bit-flip errors in integrated circuits can be caused by alpha particles. As the size of integrated circuits become smaller radiation-induced faults, such as single-event upsets (SEUs) and multi-bit upsets (MBUs), are becoming more common. An SEU or MBU can occur when a particle passes through an integrated circuit. Upon impacting an integrated circuit, the particle may convert its kinetic energy to electrical energy which can be deposited in the circuitry. This energy can affect the state of the circuitry, for example flipping a bit, if the deposited energy exceeds the energy level which is required to hold the correct state. An SEU occurs when a particle changes the state of a single circuit element and an MBU occurs when a particle changes the state of two or more circuit elements. Cosmic rays and other common radiation types can result in SEUs and MBUs in integrated circuits. As integrated circuits continue to decrease in size, lower energies are needed to change the internal state of the circuitry. Therefore, radiation-induced faults are becoming a reliability concern for modern integrated circuits.
Currently faults in integrated circuits, such as MBUs, can be detected and/or corrected through the use of advanced error control techniques. However, such advanced error control techniques require substantial overhead and are accordingly undesirable.